(defun predicat (alist)

    (progn

    	    (mapcar 

	     #'(lambda (v)  

		(unless 

		(integerp v) 

		(return-from predicat "not all integer (FALSE)"))

		) alist )

	     (return-from predicat "all integer (TRUE)") 	

    )	

)

 

(predicat (list 0 1 2 3 4 6 7   ))

(predicat (list 0 "V" 2 3 4 6 7 ))